In general, a handoff is a process of transferring a data session from one cell to another without interruption of a related service. The handoff enables a user equipment to seamlessly receive a service even when the user equipment travels from one cell to another. Such a cell-to-cell handoff has been applied to homogenous networks. Lately, handoff has been advanced to transfer a data session between different types of networks.
Handoff between different types of networks, for example, from a mobile network to a wireless data network, is frequently performed to improve a service quality or to reduce a service charge. In order to handoff from a mobile network to a wireless data network, user equipment needs to frequently search accessible wireless data networks in the vicinity of the current location of the user equipment. For example, a user equipment frequently searches for a Wi-Fi service area or a Wi-Fi access point using a Wi-Fi modulator-demodulator (MODEM) in order to handoff from a wideband code division multiple access (WCDMA) network to a Wi-Fi network. Such frequent searching of a Wi-Fi access point significantly increases overall power consumption of the user equipment.